1. Field of the Invention
The present invention generally relates to automobile control pedals, such as brake, clutch and accelerator pedals. More specifically, this invention relates to an adjustable automobile control pedal system whose pedals can be selectively adjusted to allow optimal positioning of the pedals relative to the driver of the automobile.
2. Description of the Prior Art
Automobiles are conventionally provided with foot-operated control pedals, such as an accelerator, brake and clutch pedal that are used in the control of motion and speed of the automobile. Typically, these control pedals are permanently fixed to the vehicle body and rotate or pivot away from the driver when foot pressure is applied, and are not adjustable relative to the driver or their respective attachment points. Consequently, the control pedals must generally be attached so as to be positioned relative to the driver of the vehicle to afford operation that is adequately safe and comfortable for the "average" driver. However, some adjustment of the driver's position relative to the control pedals is clearly desirable since the vehicle and its controls must accommodate drivers of various physical attributes.
Though the driver's seat is usually mounted so as to be slidable in a fore and aft and up and down direction to accommodate drivers of different physiques, such an arrangement is only partially effective in positioning the driver relative to the control pedals. Seat adjustment allows the driver to position himself or herself relative to the automobile's steering wheel and the control pedals, to some degree improving the driver's comfort and facilitating the driver's ability to operate the vehicle's primary controls. It is, however, nearly impossible for such a solution to accommodate all possible variations in the human frame. In particular, proportional differences between the lengths of a driver's arms, legs and feet in relation to the driver's overall physique cannot be readily accommodated by merely adjusting the seat fore and aft or up and down with respect to the control pedals. Accordingly, it has been recognized that some form of control pedal adjustment is desirable to provide optimal comfort and safety to the driver while also ensuring that the driver can fully operate the control pedals at all times.
Lever mechanisms, of course, are known in the prior art. The adjustment of one lever with respect to another concentrically mounted lever can also be found in wear or slack adjuster mechanisms. For example, Tack et al., U.S. Pat. No. 2,550,731, and Tack et al., U.S. Pat. No. 2,550,732, teach a manually operated screw mechanism threaded into one lever and operatively connected to associated hangers for adjusting the slack conditions in the brake rigging by adjustment with respect to the hangers and simultaneously modifying the position of the brake lever where it is connected to the associated brake rigging to allow for further wear adjustment.
Many approaches to providing adjustable control pedals have been suggested in the prior art. One approach is to provide some form of ratchet device that allows the entire control pedal assembly to rotate about a primary pivot point. This approach rotates a housing to which the control pedals are each rotatably attached, thus providing rotation of the control pedals in unison relative to the driver. Examples of this approach are illustrated in U.S. Pat. No. 3,282,125 to Dully, U.S. Pat. No. 3,400,607 to Smith, and U.S. Pat. No. 3,563,111 to Zeigler. A similar approach is to mount one or more control pedals to a housing, attached to the body of the vehicle, which is slidable fore and aft as a unit relative to the driver, as illustrated in U.S. Pat. No. 2,860,720 to Huff et al., U.S. Pat. No. 4,683,977 to Salmon, U.S. Pat. No. 5,010,782 to Asano et al., and British Patent No. 952,831 to Mussell. As taught by Asano et al., the entire housing and pedal assembly rotates about a single pivot point during actuation of the pedals. A disadvantage with pedal systems such as that of Asano et al. is that a spring is required to return the pedal and housing assembly to its initial position, necessitating that the driver also overcome the force generated by the spring in order to actuate the pedal, resulting in an increase of brake pedal effort.
Another suggested approach is a variation on the two previously mentioned, employing a screw-actuated device to displace a housing to which one or more control pedals are rotatably mounted. The screw-actuated device can be used to either rotate the entire housing about a pivot point, as shown in U.S. Pat. No. 3,151,499 to Roe, or the screw-actuated device can displace the housing fore and aft, as illustrated by U.S. Pat. No. 3,301,088 to White; U.S. Pat. No. 3,643,525 to Gibas; U.S. Pat. No. 3,765,264 to Bruhn, Jr.; U.S. Pat. No. 4,870,871 to Ivan; U.S. Pat. No. 4,875,385 to Sitrin; U.S. Pat. Nos. 4,989,474 and 5,078,024 to Cicotte et al.; and U.S. Pat. No. 5,460,061 to Redding, et al. Typically, the screw-actuated device is disclosed to be driven by an electric motor, which allows the control pedals to be selectively adjusted by the driver from an appropriate actuator switch mounted on the dashboard of the vehicle within the driver's reach.
A further attempt to provide a solution for this problem is disclosed by Rixon et al. in U.S. Pat. No. 5,632,183, wherein a pedal assembly is mounted on a single hollow guide rod extending forwardly from a transmission housing that is pivotably mounted to a bracket secured to a body portion of the vehicle. A helical ball and nut assembly is positioned within the single hollow guide and extends from the transmission housing. A key extends from the nut to the pedal assembly that is mounted to the outside diameter of the single hollow guide so that linear movement of the nut along the helical thread within the hollow guide generates linear movement in forward or rearward directions of the pedal assembly along the hollow guide rod.
As can be readily appreciated by those skilled in the art, the above examples all require substantial hardware and space beneath the automobile's instrument panel to accommodate the device and its associated structure providing the adjustment features. Much of the necessary additional hardware can be attributed to the need to avoid affecting the operation of the brake and/or clutch pedals, during adjustment, with their respective power sources. Specifically, the approach chosen must avoid causing the brake pushrod and accelerator cable attachment points that actuate the respective brake and accelerator components to be displaced relative to their designed positions so as to ensure operation within the correct operational characteristics of the brakes, clutch, and/or accelerator pedals.
In addition, it is generally preferable that the approach chosen have no effect on the mechanical advantage of the brake control pedal as determined by the brake control pedal's orientation relative to the brake pushrod. Generally, the mechanical advantage of a control pedal can be described as the relative effort required to apply the brake pedal as compared to the actual force required to actuate the adjustment device associated with the brake pedal. For instance, mechanical advantage can be increased by moving the contact point between the brake pedal and the brake cylinder's pushrod toward the pivot point of the brake pedal.
To avoid changing the mechanical advantage, the adjustable control pedal assemblies of the prior art generally teach a device in which the control pedals are independently adjusted so as to produce no adverse effect with respect to repositioning of the pedal pivot point relative to the pushrods of the respective operating cylinders, as can be seen with the teachings of Cicotte et al. in U.S. Pat. Nos. 5,351,573, 5,771,752 and 5,823,064. Alternatively, the adjustment device must be provided with a mechanism that simultaneously adjusts the length of the pushrod to accommodate the displacement of the control pedal assembly, as seen with the teachings of Bruhn, Jr.
Though regarding an unrelated and non-analogous problem associated with optimizing the mechanical advantage of a control pedal, U.s. Pat. No. 3,798,995 to Schroter teaches the use of a variable-ratio control pedal utilizing a camming contour for amplifying the mechanical advantage of the control pedal in the latter stages of the control pedal stroke. The intent with such a device is to maximize the driver's braking effort without the need for excessive forces applied to the control pedal. However, the teachings of Schroter are directed entirely toward achieving an optimal mechanical advantage and do not provide any adjustment of the control pedals with respect to the position of the driver. Further, Schroter does not teach or suggest a solution to the problem of adjusting the positions of the control pedals, nor does Schroter even recognize the problem to which the above prior art is directed.
From the above discussion, with the exception of the recent Cicotte patents, it can be readily appreciated that the prior art does not disclose an automobile control pedal arrangement that can be adjusted to adapt to the particular physiological requirements of a driver, while simultaneously avoiding the requirement of mounting the entire control pedal assembly to a housing that is either pivotable or displaceable relative to the position of the driver, without affecting the brake effort, however small. Nor does the prior art teach or suggest an apparatus that entails minimal additional hardware to achieve suitable adjustment of one or more control or accelerator pedals to the effect that no repositioning of the prior art pivot point locations is required and, therefore, no significant structural changes need be made to a conventional control pedal arrangement.
Although, generally, repositioning of an attachment or pivot point is unacceptable because of its effect on brake/accelerator/clutch pedal forces or efforts, the specifications for angular variations are more generous because small angular variations with respect to current pivot point locations have little or no effect on the operational parameters, i.e., brake/clutch effort.
Accordingly, what is needed is a cost-efficient adjustment device for adjusting one or more automobile brake/clutch control and/or accelerator pedals, as well as footrests. The adjustment device is capable of spatially adjusting the control pedals without repositioning the pivot attachment of the conventional control pedal arrangement to adapt to the physical and physiological demands of a driver, and is simultaneously cost effective by requiring minimal structural components and modifications to achieve the desired functional and safety results.